Changeset 5855 for branches/QAP/HeuristicLab.Analysis/3.3/MultidimensionalScaling

Timestamp:

03/29/11 01:42:41 (14 years ago)

Author:

abeham

Message:

#1330

• Fixed calculation of normalized stress value
• Fixed a few bugs

File:

• branches/QAP/HeuristicLab.Analysis/3.3/MultidimensionalScaling/MultidimensionalScaling.cs (modified) (3 diffs)

branches/QAP/HeuristicLab.Analysis/3.3/MultidimensionalScaling/MultidimensionalScaling.cs

@@ -61 +61 @@
       double epsf = 0;
       double epsx = 0;
-      int maxits = 1000;
+      int maxits = 100;
       alglib.mincgstate state = null;
       alglib.mincgreport rep;
@@ -69 +69 @@
           double[] c = new double[] { coordinates[i, 0], coordinates[i, 1] };
 
-          if (iterations == 0 && i == 0) {
-            alglib.mincgcreate(c, out state);
-            alglib.mincgsetcond(state, epsg, epsf, epsx, maxits);
-          } else {
-            alglib.mincgrestartfrom(state, c);
+          try {
+            if ((iterations == 0 && i == 0)) {
+              alglib.mincgcreate(c, out state);
+              alglib.mincgsetcond(state, epsg, epsf, epsx, maxits);
+            } else {
+              alglib.mincgrestartfrom(state, c);
+            }
+            alglib.mincgoptimize(state, StressGradient, null, new Info(coordinates, distances, i));
+            alglib.mincgresults(state, out c, out rep);
+          } catch (alglib.alglibexception e) { }
+          if (!double.IsNaN(c[0]) && !double.IsNaN(c[1])) {
+            coordinates[i, 0] = c[0];
+            coordinates[i, 1] = c[1];
           }
-          alglib.mincgoptimize(state, StressGradient, null, new Info(coordinates, distances, i));
-          alglib.mincgresults(state, out c, out rep);
-
-          coordinates[i, 0] = c[0];
-          coordinates[i, 1] = c[1];
         }
       }
@@ -112 +115 @@
 
     public static double CalculateNormalizedStress(int dimension, DoubleMatrix distances, DoubleMatrix coordinates) {
-      double stress = 0;
+      double stress = 0, normalization = 0;
       for (int i = 0; i < dimension - 1; i++) {
         for (int j = i + 1; j < dimension; j++) {
           if (distances[i, j] != 0) {
-            stress += Stress(coordinates[i, 0], coordinates[i, 1], distances[i, j], coordinates[j, 0], coordinates[j, 1])
-              / (distances[i, j] * distances[i, j]);
+            stress += Stress(coordinates[i, 0], coordinates[i, 1], distances[i, j], coordinates[j, 0], coordinates[j, 1]);
+            normalization += (distances[i, j] * distances[i, j]);
           }
         }
       }
-      return stress;
+      return Math.Sqrt(stress / normalization); ;
     }